BACKGROUND OF THE INVENTION
This present disclosure relates to trailers, specifically the attachment between the trailer and a towing vehicle. Commonly, when being towed by a vehicle, the trailer is subject to transient forces as the towing vehicle pulls the trailer over various terrains or when loads are moved or placed on the trailer. Trailers have a tongue weight that is borne by the hitch ball attached to the towing vehicle, commonly at or near the rear bumper. While driving, transient forces on the trailer can translate to transient tongue forces transmitted to the towing vehicle, at the very least, can be unsettling to the driver. In an extreme situation, the transient tongue forces can create a dangerous loss of control. An improved adapter that can be affixed directly to the trailer and the towing vehicle is necessary.
SUMMARY OF THE INVENTION
The present disclosure describes a torsion adapter that is added to a trailer between the tongue of the trailer and an adjustable trailer coupler. The torsion adapter has a trailer mounted side and a coupler mounted side with torsion arms that connect the sides. The trailer side has an upper and lower torsion tube that each carries a corresponding torsion bar. The coupler side has an upper and lower torsion tube that each carries a corresponding torsion bar. The torsion bars have resilient cords that surround them and cause the torsion bar to resist rotation with respect to its torsion tube. The torsion arms are affixed to the terminal ends of the torsion bars to connect the sides. The trailer side and coupler side each have mounting apertures that are aligned with a plane. As force is applied between the trailer side and coupler side, the torsion adapter moves from an unloaded position to a loaded position.
BRIEF DESCRIPTION OF THE DRAWINGS
A preferred embodiment of this invention has been chosen wherein:
FIG. 1 is an isometric view of the torsion coupler affixed to a trailer;
FIG. 2 is an isometric view of the torsion coupler and trailer before assembly to the trailer;
FIG. 3 is a left side view of the torsion coupler and trailer as shown in FIG. 2;
FIG. 4 is a top view of the torsion coupler and trailer as shown in FIG. 2;
FIG. 5 is an isometric view of the torsion coupler;
FIG. 6 is a top view of the torsion coupler;
FIG. 7 is a section view 7-7 of the torsion coupler in FIG. 5;
FIG. 8 is a right side view of the torsion coupler; and
FIG. 9 is an exploded isometric view of the torsion coupler.
DESCRIPTION OF THE PREFERRED EMBODIMENT
An adjustable torsion coupler 10 is shown attached between an existing trailer 12 and an adjustable coupler 14 in FIGS. 1-4. The trailer 12 has a frame 16 with a fixed channel 18. The fixed channel 18 is rigidly affixed to the frame 16, commonly through welding or fasteners. The fixed channel 18 may be further supported by gussets 20 or other bracketry. The fixed channel 18 has a fixed channel width 24 and series of apertures 22 that are aligned with a fixed plane 26. The adjustable coupler 14 is well-known in the art and is designed to attach to a vehicle-mounted ball (not shown). The adjustable coupler 14 can be directly affixed to the trailer 12 through the fixed channel 18. The fixed channel 18 allows the adjustable coupler 14 to be affixed thereto in several different vertical positions. The adjustable coupler 14 has a mounting end 30 with a coupler width 34 and apertures 32 that align with a coupler plane 36. The adjustable coupler 14 is affixed to the torsion coupler 10 with fasteners 38.
The torsion coupler 10 has a trailer side 50 and a coupler side 52 with torsion arms 54, 56, 58, 60 connecting the two sides 50, 52. The trailer side 50 is designed to attach to the fixed channel 18 with fasteners 62, shown as bolts in FIG. 1. The trailer side 50 has identical parallel plates 64, 66 with apertures 68 that align with a tongue plane 70. The parallel plates 64, 66 are spaced apart from each other and affixed to torsion tubes 78, 80 to form a tongue portion 72 with a tongue width 74. The torsion tubes 78, 80 are a square shaped tube with rounded corners, as is typical and well-known in the art. The tongue width 74 is defined by the distance between the outer surfaces of the parallel plates 64, 66. A spacer wall 67 may be used to set the spacing and reinforce the parallel plates 64, 66. The parallel plates 64, 66 are commonly welded to the torsion tubes 78, 80, but other methods to affix them are contemplated. It is contemplated that a solid component is used that is attached to or integrated with the torsion tubes 78, 80. For example, the torsion tubes 78, 80 and tongue portion 72 could be a solid cast metal or machined component. The tongue width 74 allows the tongue portion 72 to be located in the fixed channel 18, shown in FIG. 1. The apertures 68 align with apertures 22 to allow the fasteners 62 to affix the trailer side 50 to the fixed channel 18 on the trailer 12.
The torsion tubes 78, 80 carry a corresponding torsion bar 82, 84. The torsion tubes 78, 80 are obliquely angled with respect to the tongue plane 70, as is visible in FIG. 7. Terminal ends of the torsion bars 82,84 extend beyond the ends of their corresponding torsion tube 78,80. Resilient cords 86 surround the torsion bars 82, 84. The resilient cords 86 are shown in the exploded diagram of FIG. 9 and section view FIG. 7. The resilient cords 86 are located between flat surfaces on the torsion bars 82,84 and the rounded corners of the torsion tubes 78,80. When the torsion bars 82, 84 are located their respective torsion tubes 78, 80 and surrounded by the resilient cords 86, the torsion bars 82,84 resist rotation with respect to the torsion tubes 78,80. The torsion bars 82, 84 have a corresponding central axis 92, 94. As shown in FIG. 9, the torsion bars 82, 84 are longer than the corresponding tubes 78, 80 that they reside in, so as assembled, the ends stick out on either side. A fastener 96 extends through an aperture in the torsion arm 54,56,58,60 and affixes the torsion arm to the corresponding torsion bar 82,84 by threading into a threaded hole 88 in the end of its respective torsion bar 82,84. Torque and other forces between the torsion bars 82,84 and torsion arms 54,56,58,60 are carried by the bolts and the interfaces between the pockets and the ends of the torsion bars 82,84. As shown, the torsion bars 82, 84 are primarily square shaped in their cross section, but it is contemplated that other shapes are possible. The torsion arms 54, 56, 58, 60 have corresponding pockets 90 that receive the ends of the torsion bars 82,84. The square shape fits into the receiving pocket 90 that rotationally affixes the torsion bar 82, 84 to its corresponding torsion arm 54, 56, 58, 60. A fastener 96 holds the torsion arm 54,56,58,60 to its corresponding torsion bar.
The coupler side 52 also has parallel plates 104, 106 that are affixed to torsion tubes 108, 110. As is visible in FIG. 7, the torsion tubes 108,110 are obliquely angled with respect to a channel plane 120. A coupler channel 112 is also affixed to the parallel plates 104, 106 and has a channel width 114. These components are commonly affixed through welding or other metal joining methods. The coupler channel 112 includes apertures 116 that align with the channel plane 120. It is contemplated that the coupler side 52 is a solid component that is attached to or integrated with the torsion tubes 108, 110. For example, the torsion tubes 108, 110 and coupler channel 112 could be a solid cast or machined component. The torsion tubes 108, 110 carry a corresponding torsion bar 122, 124. Terminal ends of the torsion bars 122,124 extend beyond the ends of their corresponding torsion tube 108,110. Resilient cords 86 surround the torsion bars 122, 124. When the torsion bars 122, 124 are located in their respective torsion tubes 108, 110 and surrounded by the resilient cords 86, the torsion bars 122,124 resist rotation with respect to the torsion tubes 108,110. The torsion bars 122, 124 have a corresponding central axis 126, 128. As shown in FIG. 9, the torsion bars 122, 124 are longer than the corresponding tubes 108, 110 that they reside in, so as assembled, the ends stick out on either side. A fastener 96 extends through an aperture in the torsion arm 54,56,58,60 and affixes the torsion arm to the corresponding torsion bar 122,124 by threading into a threaded hole 88 in the end of its respective torsion bar 122,124. Torque and other forces between the torsion bars and torsion arms are carried by the bolts and the interfaces between the pockets and the ends of the torsion bars. As shown, the torsion bars 122, 124 are primarily square shaped in their cross section, but it is contemplated that other shapes are possible. The torsion arms 54, 56, 58, 60 have corresponding pockets 90 that receive the ends of the torsion bars. The square shape fits into the receiving pocket 90 that rotationally couples the torsion bar 122, 124 to its corresponding torsion arm 54, 56, 58, 60. A fastener 96 holds the torsion arm 54,56,58,60 to its corresponding torsion bar 122,124.
An optional load indicator 130 is shown affixed to torsion arm 54 with a fastener 132. The adjacent torsion tube 108 has a reference line 134 that is compared to the indicator 130 to determine the amount of torque applied to the torsion arm 54 and torsion bar 122.
In use, the torsion coupler 10 is commonly subject to a downward force on the trailer side 50 (from the trailer tongue weight) and an upward force on the coupler side 52 (from the towing vehicle supporting the tongue weight). Without force acting between the coupler side 52 and trailer side, the torsion coupler 10 is in a resting position, shown in FIG. 3. In the resting position, the torsion arms 54, 56, 58, 60 are angled with respect to the tongue plane 70 and channel plane 120. As assembled to the trailer 12 and adjustable coupler 14, the tongue weight on the trailer 12, provides a downward force on the trailer side 50. When supported by the towing vehicle (not shown), the adjustable coupler 14 provides a reactive upward force that supports the tongue weight. As force that is generally parallel to planes 70, 120 is exerted between the coupler side 52 and trailer side 50, the torsion coupler 10 moves from the resting position toward a loaded position. The loaded position causes the torsion arms 54, 56, 58, 60 to become more flat and increased loads may cause the arms to angle upward. As force is applied, the force creates rotation in the torsion bars 82, 84, 122, 124 about their corresponding axes 92, 94, 126, 128. Because the torsion bars 82, 84, 122, 124 and torsion arms 54, 56, 58, 60 are coupled together, the coupler side 52 moves vertically with respect to the trailer side 50 and remains parallel throughout that movement. In particular, the tongue plane 70 remains parallel to the channel plane 120. Axis 140 intersects axes 126 and 128 and remains fixed with respect to the channel plane 120. Axis 142 intersects axes 92 and 94 and remains fixed with respect to the tongue plane 70. An upper arm axis 144 intersects axes 92, 142, 126 and 140. A lower arm axis 146 intersects axes 94, 142, 128, and 140.
To install the torsion coupler 10 on an existing trailer, the coupler 14 (if any) is removed from the fixed channel 18 by removing the fasteners 62 from the fixed channel 18. The tongue portion 72 is placed into the fixed channel 18 and the apertures 22, 68 are aligned. Depending on the length of the fixed channel 18 and number of apertures 22, the user may have the flexibility to locate the tongue portion 72 at different vertical positions. Fasteners 62 are installed and tightened down. The user selects the desired height of the adjustable coupler 14 by aligning apertures 32 with apertures 116 in the coupler channel. Fasteners 38 are tightened down to affix the adjustable coupler 14 to the torsion coupler 10. The user then couples the adjustable coupler 14 to the towing vehicle (not shown). As installed, the torsion coupler 10 is attached with the coupler channel 112 parallel to the fixed channel 18 of the trailer. As load is applied, the torsion bars and torsion arms rotate, and the coupler channel 112 remains parallel to the fixed channel 18 of the trailer.
It is understood that while certain aspects of the disclosed subject matter have been shown and described, the disclosed subject matter is not limited thereto and encompasses various other embodiments and aspects. No specific limitation with respect to the specific embodiments disclosed herein is intended or should be inferred. Modifications may be made to the disclosed subject matter as set forth in the following claims.